As you all know, the final episode of "Oshi no Ko" received mixed reactions. I personally love bad endings and endings that leave you with a lingering feeling, so I have no complaints at all.
...However, I do feel that the ending was a little rushed.
I've tried to think about why this happened!
① Did they want to end it in a volume that's a multiple of 4? The "Oshi no Ko" anime usually covers 4 volumes per season. So, either the anime production team requested it, or Aka-sensei considered ending it in a volume that's a multiple of 4 → couldn't draw up to volume 20 → crammed into volume 16.

Regarding the ending of [Oshi no Ko] | 有馬かな無限恒久永遠推し!!!'s post